Infectious Diseases, April 2002 Journal Scan
From
The Lancet
March 9, 2002 (Volume 359, Number 9309)
Association Between Simian Virus 40 and Non-Hodgkin Lymphoma
Vilchez RA, Madden CR, Kozinetz CA, et al
The Lancet. 2002;359(9309):817-823
For some time, it has been known that simian virus 40 (SV40) can cause cancer
in animals and may be associated with a number of human malignancies.[1] This
report and another in the same journal[2] suggest a strong association between
SV40 T antigen DNA sequences and diffuse large cell and follicular non-Hodgkin's
lymphoma. There is now a plausible explanation for this relationship,[3] and
there may be implications for sero-screening and surveillance of potentially
infected populations.
The authors, from the Baylor College of Medicine, Houston, Texas, obtained tumor
specimens from 76 HIV-positive and 78 HIV-negative patients with various lymphomas,
as well as specimens from patients with colon and breast cancer. They extracted
total cellular DNA from tumors and subjected them to stringent PCR assay for
the SV40 T antigen gene as well as markers of other viruses including EBV, JC,
BK, and human herpesvirus 8 (HHV-8). They followed this by Southern blot hybridization
and DNA sequencing to specify viral genomic sequences.
SV40 T antigen sequences were found in 42% of 154 non-Hodgkin's lymphomas, in
no normal lymph nodes, and in none of the control cancer specimens. This result
was identical to the 43% rate of detection in non-Hodgkin's lymphomas in the
accompanying article.[2] HIV seropositivity did not appear related to presence
of SV40.
This article is of concern because millions were exposed to SV40-contaminated
lots of polio vaccine between 1955 and 1963. SV40 has fulfilled Koch's postulates
as a cause of cancer.[3] Recent evidence suggests that the T antigen, in fact,
inhibits function of the proteins of the p53 and Rb tumor-suppressor genes.
This is the same mechanism thought operative with the E6 and E7 proteins of
human papillomavirus. This appears to be a necessary, but perhaps not sufficient,
cause for malignancy, and might be a future target for antiviral therapy.References
1. Butel JS, Lednicky JA. Cell and molecular biology of simian virus 40: implications
for human infections and disease. J Natl Cancer Inst. 1999;91:119-134. Abstract
2. Shivapurkar N, Harada K, Reddy J, et al. Presence of simian virus 40 DNA
sequences in human lymphomas. Lancet. 2002;359:851-852. Abstract
3. Malkin D. Simian virus 40 and non-Hodgkin lymphoma. Lancet. 2002;359:812-813.
Abstract